Defects play an important role on the unique properties of the sp2-bonded materials, such as graphene. The creation and evolution of mono-vacancy, di-vacancy, Stone-Wales (SW) and grain boundaries (GBs) under irradiation in graphene are investigated using density functional theory and time-dependent density functional theory molecular dynamics simulations. It is of great interest to note that the patterns of these defects can be controlled through electron irradiation. The SW defects can be created by electron irradiation with energy of above the displacement threshold energy (Td, ~19 eV) and can be healed with an energy (14-18 eV) lower than Td. The transformation between four types of divacancies, V2(5-8-5), V2(555-777), V2(5555-6-7777) , and V2(55-77) can be realized through bond rotation induced by electron irradiation. The migrations of divancancies, SW defects, and GBs can also be controlled by electron irradiation. Thus, electron irradiation can serve as an important tool to modify morphology in a controllable manner, and to tailor the physical properties of graphene.
Revised: September 12, 2012 |
Published: August 2, 2012
Citation
Wang Z., Y. Zhou, J. Bang, M.P. Prange, S. Zhang, and F. Gao. 2012.Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations.Journal of Physical Chemistry C 116, no. 30:16070-16079.PNNL-SA-89161.doi:10.1021/jp303905u